直流变换器并联系统动态均流的非线性控制

THE NONLINEAR DYNAMIC CURRENT SHARING CONTROL OF PARALLELED DC/DC CONVERTER

基于微分几何理论,该文针对并联直流变换器提出了一种新颖的非线性动态均流控制策略。文章首先利用开关脉冲分段函数建立了两相交错并联变换器两输入两输出仿射非线性模型,推导出对应的非线性坐标变换矩阵和非线性状态反馈规律表达式,得到状态反馈精确线性化模型。接着文章利用二次型最优控制对线性化模型进行动态均流控制设计,得到精确线性化的状态反馈规律,建立了一种基于微分几何理论的非线性均流控制策略。研究表明,两相并联直流变换器通过状态反馈精确线性化得到的非线性均流控制策略,比现有PID均流控制有更好的动态均流特性,同时具有较好的动态和稳态品质。

Based on the differential geometry theory, this paper proposes a novel nonlinear dynamic current sharing control strategy on paralleled DC/DC converter. A standard nonlinear model of two-phase interleaved DC/DC converter with double input and double output is set up by applying switching impulse method, The related nonlinear coordinate transform matrix and the equations of nonlinear feedback principles are obtained, which lead to a new state variable feedback linearization model. Based on the linearization model, the paper then uses linear optimal control strategy to design the feedback principles of corresponding linearization model. Thus it achieves a novel nonlinear dynamic current sharing control on differential geometry theory. Research shows that the proposed nonlinear current sharing control with better steady and dynamic performances can acheive better dynamic current sharing, compared with the conventional Proportional Integral Differential（PID） current sharing control.